Door closing apparatus



April 11,1939 c. w. HARTSHORN DOOR CLOSING APPARATUS 2 Z ZZ'moentor jf w (Ittorneg Patented Apr. 11, 1939 UNITED STATES PATENT OQFFIQE 5 Claims.

My invention relates to improvements in door closing apparatus.

One of the objects of my invention is the provision of, a novel apparatus for closing a door, 5 which will automatically close a door after it has been swungto a predetermined open position and then released, and which will permit the door to remain open after it has passed said predetermined position in its opening movement.

, A further object of my invention is the provision of a novel door closing apparatus which is simple, cheap, strong, durable, not likely to get out of order, which will close without slamming, and which is efiicient in operation.

Still another object of my invention is the provision of a novel door closing apparatus for application to a door that will swing in either direction from a closed position, and which will swing the door automatically to the closed position, after the door has been swung open in either direction.

A further object of my invention is the provision of a novel piston adapted for use in a door closing apparatus.

5 The novel features of my invention are hereinafter fully described and claimed.

In the accompanying drawing which illustrates my invention,

Fig. 1 is a side elevation showing one form of my invention operatively mounted, the door being shown closed, part of the cylinder being broken away.

Fig. 2 is a top view of the apparatus shown in Fig. 1, the door and jamb being shown in horizontal section, and the door swung to and held by the apparatus in an open position.

Fig. 3 is a view similar to Fig. 2, with the door shown opened to a position in which the apparatus will close the door.

Fig. 4 is an enlarged longitudinal sectional view, partly broken away, of my improved piston, shown mounted in a cylinder.

Fig. 5 is an enlarged fragmental view, partly in elevation and partly in longitudinal section, showing one end portion of the cylinder and a portion of the piston.

Fig. 6 is an enlarged edge view of one of the split rings.

Fig. 7 is an end elevation of what is shown in Fi 6.

Fig. 8 is a reduced stretch out view of one of the split rings.

Fig. 9 is a top view of a modified form of my invention shown operatively mounted on a door, the

tion, the door being of a type which will swing in either direction from the closed position, the door being shown in solid lines in the closed position, and shown, partly broken away in dotted lines in an open position.

Fig. 10 is an elevation, partly broken away, of the form of apparatus shown in Fig. 9, with the door shown closed.

Similar reference characters designate similar parts in the different views.

Referring to Figs. 1 to 8, l designates a door hinged on a vertical axis 2 to a jamb 3, the opposite jamb being designated by 4.

5 designates a horizontal cylinder hinged on a vertical axis 6 at one end to a bracket 1 fastened to one side of the door I. Said end of the cylinder 5 is provided with an air passage 8, adapted to be partly closed by an adjustable screw 9, whereby the door is caused to close easily and without slamming, by permitting a slow passage of air out of the cylinder.

The other end of the cylinder 5 is externally threaded and has fitted on it a removable cap l having a central hole in which is loosely fitted a piston rod l I having at its outer end an integral bifurcated portion l2, provided at opposite sides respectively with two pins l3 to which are respectively attached one set of ends of two coil springs M the other set of ends of which are attached to two oppositely disposed pins l provided on the distant end of the cylinder 5. The tension of the springs l4 normally tends to force the piston rod II inwardly, for the purpose of closing the door I after it has been opened, as will be later explained.

The arms l6 of the bifurcated end of the piston rod, are spaced apart and are pivoted on a vertical axis comprising a pin ll to the bifurcated end of a member l8, the other end of which has a threaded hole in which is fitted one end of a rod I 9. The member l8 and rod l9 comprise a link, which is extensible and contractible as to length by removing the axis pin I l and-revolving the member IB to the desired position on the rod IS in which it is held after the pin I1 is reinserted therethrough. The other end of the rod I9 is pivoted on a vertical axis comprising a pin 20 mounted in two brackets Zl at opposite sides of the rod l9 and fastened on the jamb 3, and forming a projection thereon. The axis pin 20 is spaced from the door axis 2. Instead of removing the axis pin ll, the rod 19 may be adjusted in the member l8 by removing the axis pin 20. Pivoted on the axis pin I1 is one end of a rod 22, the other end of which is threaded and fitted in a threaded hole in a member 23 which is pivoted on a vertical axis by a pin 24 mounted at a substantial distance from the axis and the adjacent side of the door I in a bracket 25 on the door. The bracket 25 forms a projection on the door. The rod 22 and member 23 form a link which is extensible and contractible by turning the rod 22 in the member 23, which can be done by removal of either pin I1 or 24.

The axis pin 24 is spaced at substantial distances from the pins I1 and 20.

The piston rod adjacent to its inner end is provided with an annular abutment comprising an annular flange 26 which on the side next the inner end of the rod II has a recess in which is fitted a circular collar 21 of fiexible material, such as soft rubber or leather, which collar serves as a gasket for closing a circular central recess 28 in the adjacent side of a head 29 provided at the left end, as viewed in Fig, 4, of a sleeve 30 slidably fitted on the rod II at the right of the abutment flange 26.

The inner end of the piston rod II is provided with a longitudinal hole 3| which has its inner end extending laterally to the periphery of the rod II, and which is at all times in communication with the recess 28 in the head 29. When the head 29 is spaced from the gasket or collar 21, as shown in Fig. 4, air from the left of the head 29 can pass from the cylinder through the recess 28 and hole 3| to the other side of the piston head, of which the head 29 forms a part.

Next to the head 29, at the right thereof, as viewed in Fig. 4, and bearing against the head is a flexible cup 32, of material, such as soft rubber or leather, the periphery of which cup has slidable engagement with the inner wall of the cylinder 5.

Located in the cup 32 is a cup expanding member comprising a resilient split ring 33, Figs. 4, 6 and 8, the tension of which by the ring bearing against the inner wall of the cup 32, forces the latter tightly against the cylinder wall. The other part of the cup expanding member comprises a flat ring plate 34 having a portion of its periphery 35 integral with one edge of the split ring 33 at a point opposite to the split portion of the ring 33. The ring 34 has a large central hole through which extends a clamping collar 36 slidable on the sleeve 30 and having its left end, Fig. 4, tightly bearing against a washer 36' holding the latter against the cup 32.

When more than one cup is provided in the piston head, a ring plate 31 is fitted on the sleeve 30 and bears against the adjacent end of the collar 36, Fig. 4. Another cup 32', like the cup 32, is mounted on the sleeve 30 and bears against the ring plate 31. The cup 32' has fitted in it another split ring 33', like the split ring 33, which ring 33 presses the wall of the cup 32 against the cylinder 5. The ring plate portion 34 of the split ring 33 encircles the sleeve 30, its movement to the right, Fig. 4, being limited by contact with a nut 38 fitted on the right threaded end of the sleeve 3|], and bears against a washer 31, which bears against and holds the cup 32' tightly against the ring plate 31, whereby the parts of the piston head are held operatively assembled and slidable on the piston rod A coil spring 39 encircles the piston rod II and bears at its left end against the right end of the sleeve 3|], Fig. 4, its right end bearing against a nut 40 fitted on the threaded right end of the piston rod II. The tension of the spring 39 normally forces the head 29 against the abutment gasket 21, for preventing air passing to the left through the hole 3| in the piston rod I I, when the latter and the piston head move to the right.

In the operation of the form shown in Figs. 1 to 8, when the door I is swung from the closed position, shown in solid lines in Figs. 1 and 3, to the partly open position, shown in dotted lines in Fig. 3, the link comprising the rod 22 and the member 23, and the link comprising the member I8 and the rod I9, will draw the piston rod outwardly against the tension of the springs I4, upon which the air pressure in the cylinder 5, at the left of the piston head, will slide the latter to the right on the piston rod II, thus opening the air passage formed by the recess 28 and the hole 3|, and permitting air to pass through said passage, thus permitting the piston headto be drawn to the left, Fig. 4, with small resistance.

When the door I is released from the open position shown in Fig. 3 in dotted lines, the springs'l4 will by pulling on the piston rod II force the piston rod inwardly, thus through the connections of the piston rod with the door and jamb 3, before described, causing the door to swing to the closed position, such closing movement, however, being resisted by the piston head, which will be slid to the left, as viewed in Fig. 4, thus closing the air passage 3|, and causing the cups 32 and 32' to be expanded by air pressure and by the split rings 33 and 33.

The door I will thus close slowly and without slamming.

If the door I is swung open, to or past the dead center or predetermined position, in which the longitudinal center line of the piston rod alines with the axis pin 24, or past such axis pin, as shown in Fig. 2, the coil springs I4 can not close the door, but in the position shown in Fig. 2, the springs would tend to hold the door open. By swinging the door manually past the dead center position toward the closed position, the springs I4 would then close the door as before described. The door is held in the open position, shown in Fig. 2, due to the link |8|9 having a length such that the distance between its axis 20 and the pivotal connection I1 with the piston rod is such that the said pivotal connection will be between the door I and a plane through the axis 24 parallel with the door.

The split rings 33 and 33 are movable radially in all directions, so as to always exert pressure evenly around the walls of the cups 32 and 32.

Instead of employing two springs I4 to close the door, a coil spring 4|, Fig. 5, may encircle the piston rod II, and have one end bearing against the abutment 26, and its other end hearing against the cap III, the tension of the spring 4|. serving to move the piston to close the door.

The cap ID has the piston rod loosely fitted in it, so as to permit air to enter through the cap into the cylinder 5, when the door is closing. The screw 9 regulates the speed at which the door can close, by the amount that it closes the air passage 8 through which the air escapes from the cylinder 5, when the piston is moving in a direction to close the door.

In the form shown in Figs. 9 and 10, the door 42 is of the type having its upper end spaced a substantial distance from the upper end of the door frame, and it is pivoted to the jamb 43 on a vertical axis 44. A cylinder 45 corresponding to the cylinder is pivoted at one end on a vertical axis on a post 46 mounted on the top of the door 42.

Slidable in the cylinder 45 is a piston corresponding in most respects to the piston shown in Figs. 1 and 4, and having its piston rod 41 pivoted on a vertical axis 48 to a member 49 having threaded engagement, and adjustable toward and from the jamb 43, with a member 50. Said members 49 and 50 constitute a bracket pivoted to the piston rod and fastened to the jamb 43.

The piston head 5| is similar in structure and function to the one shown in Fig. 4, and it has bearing against it a coil spring 52, which encircles the rod 41 and bears against the end of the cylinder 45 which is adjacent to the jamb 43.

The door 42 can swing in either direction from the closed position, shown in solid lines in Fig. 9, in which latter figure it is shown in dotted lines swung in one direction from the closed position.

When swung open in either direction, the spring 52 will close the door, or gate as the case may be, and the piston head 5! will operate the same as the one shown in Fig. 4, to resist the too rapid closing of the door or gate.

In the form shown in Figs. 1, 2 and 3, the piston rod II is bifurcated at its outer end to enable it to pass the dead center line which is the axis 24. This is effected by having the arms l6 of the piston rod I I disposed and so spaced apart, as to enable the bracket 25 to pass between the arms l6, as shown in Fig. 2, when it is desired to have the door stay open. If desired, either arm I 6 could be eliminated, and one of them only be employed to efiect the function now effected with both.

Other modifications of my invention, within the scope of the appended claims, may be made without departing from the spirit of my invention.

What I claim is:

1. In a door closing apparatus, the combination with a door jamb and a door hinged thereto on a vertical axis and having a projection spaced from said axis, of two links, one pivoted to said door projection on an axis spaced from said door axis, the other link being pivoted to the jamb on an axis spaced from the axis of the door axis and the axis of the first named link, a cylinder attached to the door, a piston having a head reciprocative in said cylinder and having a piston rod pivoted to said two links at a point such that, when the door is swung from a closed position to a predetermined open position, the longitudinal central line of said piston will pass from one side of the axis in said door projection into alinement therewith, and yielding means for moving said piston to close the door when said central line of the piston is at said one side of said axis in the door projection.

2. In a door closing apparatus, the combination with a door jamb and a door hinged thereto on a vertical axis and having a projection spaced from said axis, of two links, one pivoted to said door projection on an axis spaced from said door axis and from the side of the door, the other link being pivoted to the jamb on an axis spaced from said door axis and from the axis of the first named link, a cylinder attached to the door, a piston having a head reciprocative in said cylinder and having a piston rod pivoted to said two links at a point such that, when the door is swung from a closed position past a predetermined open position, said piston rod will pass from one to the other side of said axis in said door projection, and yielding means for moving said piston to close the door when said piston rod has passed said axis in said door projection in the reverse direction.

3. In a door closing apparatus, a cylinder, a piston rod reciprocative therein, having an abutment and having a longitudinal hole extending from one end of the piston rod to a point adjacent to said abutment and at said point extending laterally to the periphery of said piston rod to form an air outlet, a sleeve slidable on said piston rod and having a head provided with a recess always in communication with said outlet and adapted to be closed by said abutment, a flexible cup mounted on said sleeve and bearing against said head and having its periphery slidably engaging the inner wall of said cylinder, means for clamping said cup against said head, and yielding means normally forcing said head against said abutment.

4. In a door closing apparatus, the combination with a door jamb and a door hinged thereto on a vertical axis, a bracket on said jamb extending horizontally lengthwise over said door, a cylinder pivoted at one end on a vertical axis on said door and extending therefrom toward said bracket, a piston having a head reciprocative in said cylinder, the piston having a piston rod extending out of the other end of said cylinder and pivoted. on a vertical axis to said bracket between the axis of said door and the adjacent end of said cylinder, and yielding means exerting a force tending to hold said piston from moving away from said axis of said cylinder.

5. In a door closing apparatus, the combination with a door jamb and a door hinged thereto on a vertical axis and having a projection on one side spaced from said axis, of two links, one pivoted to said projection on an axis spaced from said side of the door, the other link being pivoted to the jamb at said side of the door on an axis spaced from said door axis and said link axis, a cylinder pivoted to said side of said door on an axis parallel with the door axis and the axes of said links, a piston reciprocative in said cylinder and having a piston rod pivoted to said two links at a point that will be disposed between the plane of said side of the door and a plane parallel therewith extending through said axis of said link pivoted to said projection, when the door has been swung past a predetermined open position, and yielding means for moving said piston to close the door when the door has been swung in the reverse direction toward the closed 5 position past said predetermined open position. CHESTER W. HARTSHORN. 

